Mitt always sounds like a balloon about to burst...

[Atman]

He talks and talks and talks and talks...and never takes a breath. He sounds like he's about to explode! Good thing he's wearing the magic underwear. It probably is designed to hold in the exploding soul.

[livetohike]

1. He always sounds nervous, as if he is on a job interview and I guess

he is . Good analogy with the bursting balloon.

[aint_no_life_nowhere]

2. He always sounds like a two-bit comedian who feels he has to be "on"

Romney wrinkles his brow, shakes his head while he smiles with a cheap debonair fakeness like a low-rent gigolo, while making that awful oily smooth sound in his throat as he speaks. He seems incapable of just speaking straight into the camera like a real human being.

[stevend56]

3. Pressure is mounting

I believe that as the pressure builds, Romney will look more and more desperate. He hasn't handled the campaign well so far. Chances are good that he will make big mistakes under the mounting pressure. Can you say implosion? I knew you could.

[lunatica]

4. As time goes by the thing that really bothers about Romney and his wife

Is that no matter how stupid his statements or how telling or mean or how often he gets caught in lies he and she don't have even a modicum of embarrassment or of feeling foolish or even the slightest bit of guilt.

No one can do that and be normal. I've known liars and thiefs who will look guilty or embarrassed when they're caught red handed. Not the Romneys. They never, ever look like other people do when they're caught in the glaring light of truth.

[Mayberry Machiavelli]

5. Ever since the Ryan pick he seems like someone told him to "kick it up a notch" on the stump.

It does sound like his interpretation of that is just turning up the volume and speaking in a fast pressured way. It's not particularly pleasant to listen to or persuasive. I agree with your description and noticed this too.

[grasswire]

6. amphetamines?

Is that possible?